1. Technical Field
The present invention relates to a liquid ejecting head and a liquid ejecting apparatus which eject liquid from a nozzle opening, and particularly to an ink jet type recording head and an ink jet type recording apparatus which eject ink as liquid.
2. Related Art
For example, an ink jet type recording head which is an example of a liquid ejecting head includes an actuator unit in which a piezoelectric element and a pressure generation chamber are provided, and a flow path unit having a nozzle plate in which a nozzle opening which communicates with the pressure generation chamber and ejects ink and a manifold forming substrate in which a manifold is provided which is a common ink chamber of the pressure generation chamber is provided.
A shape of the pressure generation chamber in such an ink jet type recording head is generally formed in a rectangular shape, but a pressure generation chamber is proposed which is formed in a circular shape so that merits of high driving efficiency is utilized and a driving efficiency is improved by decreasing a flexural deformation restriction of a driving unit by an electrode pad (refer to JP-A-2002-248765), or a parallelogram shape so that a structural crosstalk is decreased and the shape of the pressure generation chamber corresponds to an individual electrode in an approximate parallelogram shape (refer to JP-A-2007-237746). Here, an expression “a shape of the pressure generation chamber” means a shape of the pressure generation chamber projected on a plane parallel to the nozzle plate in which the nozzle opening is formed (hereinafter, this is similarly applied to the present specification).
However, if displacement efficiency of the piezoelectric element is improved, the possibility of failure increases due to an electrode pad.
Such a problem exists not only in the ink jet type recording head, but also in a liquid ejecting head which ejects any other liquid than ink.